Found that some epub covers (cover_with_text.png) are being generated in the WordPress root and wp-admin/ directory. Running a multisite install, but I’m getting the impression it is not multisite related.Doesn’t seem necessary to do much caching, but even so, it is integral to use a content directory.

Also wondering what the general development track looks like and whether there is any plan to updae the PHPePub version, which seems to have seen recent work: